# std::isnormal

From cppreference.com
< cpp‎ | numeric‎ | math

Defined in header `<cmath>` |  |
| (1) |
bool isnormal( float num ); bool isnormal( double num ); bool isnormal( long double num ); |  | (since C++11) (until C++23)
constexpr bool isnormal( /*floating-point-type*/ num ); |  | (since C++23)
SIMD overload (since C++26) |  |
Defined in header `<simd>` |  |
template< /*math-floating-point*/ V > constexpr typename /*deduced-simd-t*/<V>::mask_type isnormal ( const V& v_num ); | (S) | (since C++26)
Additional overloads |  |
Defined in header `<cmath>` |  |
template< class Integer > bool isnormal( Integer num ); | (A) | (since C++11) (constexpr since C++23)

1) Determines if the given floating point number num is normal, i.e. is neither zero, subnormal, infinite, nor NaN. The library provides overloads for all cv-unqualified floating-point types as the type of the parameter num.(since C++23)

S) The SIMD overload performs an element-wise `std::isnormal` on v_num. (See `math-floating-point` and `deduced-simd-t` for their definitions.) | (since C++26)

A) Additional overloads are provided for all integer types, which are treated as double.

### Parameters

num | - | floating-point or integer value
v_num | - | a data-parallel object of std::basic_simd specialization where its element type is a floating-point type

### Return value

1) true if num is normal, false otherwise.
S) A data-parallel mask object where the ith element equals true if v_num[i] is normal or false otherwise for all i in the range `[`​0​`,` v_num.size()`)`.

### Notes

The additional overloads are not required to be provided exactly as (A). They only need to be sufficient to ensure that for their argument num of integer type, std::isnormal(num) has the same effect as std::isnormal(static_cast<double>(num)).

### Example

Run this code

    #include <cfloat>
    #include <cmath>
    #include <iostream>

    int main()
    {
        std::cout << std::boolalpha
                  << "isnormal(NaN) = " << std::isnormal(NAN) << '\n'
                  << "isnormal(Inf) = " << std::isnormal(INFINITY) << '\n'
                  << "isnormal(0.0) = " << std::isnormal(0.0) << '\n'
                  << "isnormal(DBL_MIN/2.0) = " << std::isnormal(DBL_MIN / 2.0) << '\n'
                  << "isnormal(1.0) = " << std::isnormal(1.0) << '\n';
    }

Output:

    isnormal(NaN) = false
    isnormal(Inf) = false
    isnormal(0.0) = false
    isnormal(DBL_MIN/2.0) = false
    isnormal(1.0) = true

### See also

fpclassify (C++11) | categorizes the given floating-point value (function)
isfinite (C++11) | checks if the given number has finite value (function)
isinf (C++11) | checks if the given number is infinite (function)
isnan (C++11) | checks if the given number is NaN (function)
C documentation for isnormal

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/numeric/math/isnormal&oldid=149457"